The invention relates to a fan drive with a fluid-friction clutch for motor vehicles.
A fan drive of this kind has been disclosed in DE-C 33 22 779 by the applicant. In this drive, provision is made for the fan to run at increased speed at a low engine speed. In addition, at a low engine speed, provision is made for the fan to cool the radiator and/or the upstream condenser of a motor-vehicle air-conditioning system to ensure that the heat arising can be removed by a corresponding delivery of cooling air. In the case of the known drive, the fan speed is increased using a planetary gear integrated into the fluid-friction clutch by varying the transmission ratio. However, such a drive has proven unsatisfactory.